Population-level effectiveness of PMTCT Option A on early mother-to-child (MTCT) transmission of HIV in South Africa : implications for eliminating MTCT

摘要

BACKGROUND : Eliminating mother–to–child transmission of HIV (EMTCT),defined as ≤50 infant HIV infections per 100 000 live births, is a globalpriority. Since 2011 policies to prevent mother–to–child transmission ofHIV (PMTCT) shifted from maternal antiretroviral (ARV) treatment orprophylaxis contingent on CD4 cell count to lifelong maternal ARV treatment(cART). We sought to measure progress with early (4–8 weeks postpartum)MTCT prevention and elimination, 2011–2013, at national andsub–national levels in South Africa, a high antenatal HIV prevalence setting( ≈ 29%), where early MTCT was 3.5% in 2010.METHODS : Two surveys were conducted (August 2011–March 2012 andOctober 2012–May 2013), in 580 health facilities, randomly selected aftertwo–stage probability proportional to size sampling of facilities (theprimary sampling unit), to provide valid national and sub–national–(provincial)–level estimates. Data collectors interviewed caregivers of eligibleinfants, reviewed patient–held charts, and collected infant dried bloodspots (iDBS). Confirmed positive HIV enzyme immunoassay (EIA) andpositive total HIV nucleic acid polymerase chain reaction (PCR) indicatedinfant HIV exposure or infection, respectively. Weighted survey analysiswas conducted for each survey and for the pooled data.FINDINGS : National data from 10 106 and 9120 participants were analyzed(2011–12 and 2012–13 surveys respectively). Infant HIV exposure was32.2% (95% confidence interval (CI) 30.7–33.6%), in 2011–12 and33.1% (95% CI 31.8–34.4%), provincial range of 22.1–43.6% in 2012–13. MTCT was 2.7% (95% CI 2.1%–3.2%) in 2011–12 and 2.6% (95%CI 2.0–3.2%), provincial range of 1.9–5.4% in 2012–13. HIV–infectedARV–exposed mothers had significantly lower unadjusted early MTCT(2.0% [2011–12: 1.6–2.5%; 2012–13:1.5–2.6%]) compared to HIV–infectedARV–naive mothers [10.2% in 2011–12 (6.5–13.8%); 9.2% in2012–13 (5.6–12.7%)]. Pooled analyses demonstrated significantly lowerearly MTCT among exclusive breastfeeding (EBF) mothers receiving>10 weeks ARV prophylaxis or cART compared with EBF and no ARVs:(2.2% [95% CI 1.25–3.09%] vs 12.2% [95% CI 4.7–19.6%], respectively);among HIV–infected ARV–exposed mothers, 24.9% (95% CI 23.5–26.3%) initiated cART during or before the first trimester, and their earlyMTCT was 1.2% (95% CI 0.6–1.7%). Extrapolating these data, assuming32% EIA positivity and 2.6% or 1.2% MTCT, 832 and 384 infantsper 100 000 live births were HIV infected, respectively.CONCLUSIONS : Although we demonstrate sustained national–level PMTCTimpact in a high HIV prevalence setting, results are far–removed fromEMTCT targets. Reducing maternal HIV prevalence and treating all maternalHIV infection early are critical for further progress.